Method of operating a warp knitting machine

ABSTRACT

Method of operating a warp knitting machine includes, after interruption of a weft running to the weft storage and after shut-down of the machine, severing the drive connection between the weft storage and the knitting instruments, removing the length of weft extending from the break thereof to the weft storage, thereafter placing the weft storage in filling position, automatically refilling the weft reserve remaining in the weft storage, and restoring the drive connection between the weft storage and the knitting instruments so as to resume the knitting process.

United States Patent Reiners et a l. I

1451 Sept. 12, 1972 [54] METHOD OF OPERATING A WARP KNITTING MACHINE [72] Inventors: Walter Reiners; Albert tho Pesch, both of 4050' Monchengladbach,

9srma t [73] Assignee: W. Schlafhorst & Co.,..Monchengladbach, Germany [22] Filed:

May 14, 1971 [21] Appl. No.: 143,488

[30] Foreign Application Priority Data May 16, 1970 Germany ..'....P 20 24 087.3

52 U.S.Cl ..66/84 51 Int. Cl. ..D04b 23/06 58 FieldofSearch; ..66/84,158,'159

[56] References Cited 1 UNITED STATES PATENTS 3,616,656 11/1972 Furst ..66/84 Primary Examiner-Ronald Feldbaum Attorney-Curt M. Avery, Arthur E. Wilfond, Herbert L. Lerner and Daniel J. Tick [5 7] ABSTRACT Method of operating a warp knitting machine includes, after interruption of a weft running to the weft storage and after shut-down of the machine, severing the drive connection between the weft storage and the knitting instruments, removing the length of weft extending from the break thereof to the weft storage, thereafter placing the weft storage in filling position, automatically refilling the weft reserve remaining in the weft storage, and restoring the drive connection between the weft storage and the knitting instruments so as to resume the knitting process.

3 Claims, 6 Drawing Figures KNlTTlNG MACHINE MAIN DRIVE PATENTED SEP 12 I972 KNITTING MACHINE MAIN DRWE 5 2 6 IL N O E H RINN OWE NUC

FDT V AID METHOD OF OPERATING A WARP KNITTING MACHINE The invention relates to method of operating a warp knitting machine and more particularly such warp knitting machine that has a weft insertion device and a weft storage for the weft being inserted as well as a shut-down device activated at interruption of a weft running to the weft storage.

In warp knitting machines, for example Raschel knitting machines, having devices for the insertion of wefts over the entire width of the knitted fabric, the wefts are advantageously made ready by means of weft storages for transfer to the knitting instruments. By means of the weft supply thus forming, the omission of a weft in the knitted web during the slow-down phase of the warp knitting machine after a break in the weft has occurred, is sought to be avoided. Since weft breaks during the knitting operation can never fully be avoided, care must be taken that, before the knitting machine is restarted after shut-down due to a weft break, a faultless reconnection of the broken weft to the supply thereof remaining in the weft storage is achieved. For this purpose, the thread material from the weft storage that was used up during the slow-down of the machine must be replaced, and the weft supply must be restored to the required number of readied wefts. In the heretofore known machines with devices for storing wefts, the restoration of the interrupted weft filling and the connection or joining thereof to the completed knitted web is possible, however, only after burdensome seeking of the thread ends and by guiding the thread manually about each of the numerous storage members that hold the wefts in readiness. Such an operation results in long periodsof inaction and a sharp reduction in the net efficiency of the machine.

It is accordingly an object of the invention to provide method of operating a warp knitting machine which avoids the foregoing disadvantages of the heretofore known methods and which ensures, with warp knitting machines having a weft storage, that after a weft break the weft storage is rapidly refilled and the knitting process is continued free of disturbance.

With the foregoing and other objects in view, there is provided in accordance with the invention, method of operating a warp knitting machine having a weft insertion device, a weft storage for the weft that is to be inserted, a plurality of knitting instruments drivingly connectible to the weft storage, and a machine shut-down device activated at interruption of a weft being fed to the weft storage, which comprises, after interruption of a weft running to the weft storage and after shut-down of the machine, severing the drive connection between the weft storage and the knitting instruments, removing the length of weft extending from the break therein to the weft storage, thereafter placing the weft storage in weft-filling position, automatically refilling the weft reserve remaining in the weft storage, and restoring the drive connection between the weft storage and the knitting instruments for resuming the knitting process.

When a weft break occurs in the thread path between the weft supply and the weft storage, not only can the omission of a complete weft length in the knitted web be avoided by the method invention of this application in warp knitting machines having a stopping or slow-down period of especially short duration, but also the remainder of the weft supply still in the weft storage can be used again. As a result, only the thread length extending from the break in the weft to the adjacent holder member of the thread storage is initially removed in the readily accessible vicinity of one of the edges of the knitted web without any time-consuming seeking or searching therefor, and then the last weft length that has been interknitted into the web and the succeeding weft length that is still lying in the weft storage are severed from one another. Due to the severance of the drive connection between the knitting instruments and the weft storage, the latter can now be brought into the filling position thereof. By this is meant that position of the weft storage in which the very next weft to be deposited in the weft storage is directly added to the weft lengths still present in the weft storage. Therefore, no gaps, which might cause the omission of wefts in the knitted web, are produced between the individual weft lengths in the weft storage due to the slow-down of the machine before it finally stops. As soon as the weft storage is again fully provided with weft lengths, the drive connection between the weft storage and the knitting instruments can be restored and the knitting process resumed.

In accordance with another feature of the invention, the severing and restoration of the drive connection between the weft storage and the knitting instruments is effected at a predetermined clutch position so that, after a weft interruption or break, the knitting instruments per se, such as the needle bar, insertion bar, knocking-over bar and the like, upon reaching the clutch position, tend to remain in a position which affords the most favorable qualifications for re-inserting the weft from the subsequently filled weft storage and for continuing the knitting process.

In accordance with a further advantageous feature of the invention for refilling the weft storage, both the weft storage as well as a weft inserter or depositor, which serves to insert the weft, is brought into a starting position, then the weft is threaded into the weft inserter, and thereafter deposited at the weft storage in folded lengthsuFor this purpose, a thread guide traveling in a circular revolving path may serve as the weft inserter or folder, the thread guide coming to a stop at a selected point of the revolving path thereof, after the slow-down of the machine has terminated. The starting position of such a weft inserter is advantageously located in the vicinity of the edges of the knitted web since it is most readily accessible thereat and secured to the holder elements of the weft storage in an especially simple manner. After the weft end coming from the weft inserter has been deposited at the weft storage following the connection thereof to the weft still present in the weft storage, filling of the weft storage can be effected fully automatically by the weft inserter.

Depending upon the capacity of the weft storage and the weft threads still contained therein, the weft inserter executes a predetermined number of revolutions and fills with the missing number of thread lengths the weft storage which is displaced simultaneously in direction toward the yet stationary knitting instruments. When the weft which has not yet been knitted into the web after the knitting machine has come to a stop following a weft break and which has been severed from the last knitted weft in the vicinity of an edge of the knitted web preparatory to refilling the weft storage, is located again in the original position thereof at the knitting instruments, the aforementioned predetermined clutch position is attained simultaneously therewith and the drive connection between the weft storage and the knitting instruments can be restored. The knitting process per se is then continued.

Advantages deriving from the method invention of this application are especially that a weft storage, after interruption of the weft supply and an especially short slow-down period before the knitting machine comes to a final stop, can be completely refilled automatically by the weft inserter, the weft threads still remaining intact in the weft storage being useable further, and that only few manipulations are required for carrying out the method invention.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as method of operating a warp knitting machine, it is nevertheless not intended to be limited to the details shown, since various modifications may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The invention, however together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying drawing, in which:

FIG. 1 is a simplified diagrammatic plan view of part of a Raschel knitting machine with weft storage and weft filler shown in reduced scale;

FIGS. 2, 3 and 4 are diagrammatic longitudinal views of the weft filler of FIG. 1 shown in three different stages;

FIG. is an enlarged elevational view of a detail of the weft storage of FIG. 1 showing the knitting instruments in cross section; and

FIG. 6 is another view of FIG. 5 with the weft storage shown in a different angular position.

Referring now to the drawing, and first particularly to FIG. 1 thereof, there is shown a needle bar 1 having knitting needles 2 and a knitted web 3 into which a continuous weft 4 is knitted. The weft 4 comes from a supply coil 5 and, during the knitting operation, is alternatingly placed by a continuously revolving thread or weft filler 6 about the individual holder members 9 and 9a of the weft insert wheels 10 and 10a of a weft storage 11 and, in the embodiment shown in FIG. 1, is knitted into the web with each course. In the interest of clarity, and so as not to obstruct the illustrated details, those components which deliver the individual weft behind the knitting needles 2, are omitted from the figure. FIG. 1 shows, furthermore, the ends 4and 4"of the broken thread 4 which have come out of the guiding eye 7 during the slow-down movement of the thread feeder 6. The diagrammatic view of FIG. 1 shows all of the cooperating members is stationary position attained after the occurrence of a thread break and the attendant slow-down phase. It is readily apparent that due to a very short slow-down of the knitting machine, the supply of weft in the weft storage 11 in the illustrated embodiment still consists of four weft lengths which can be used further after the weft storage is refilled.

From the diagrammatic view of FIG. 2, it can be readily seen that the thread feeder 6, with the guiding eye 7 and the counterweight 8 thereof, can assume any position on the circular, rotary path 12 thereof at the moment the machine comes to a stop.

After the machine shuts down, it travels thereafter, for example at crawling speed, until it reaches a predetermined clutch position at point 13 on the revolving path 12 which corresponds to the position of the guiding eye 7 of the thread feeder 6, as shown in FIG. 3, and is held in that position. When the thread feeder 6 is accordingly held in the position shown in FIG. 3, all of the knitting instruments are also located in a position advantageous for again inserting a weft. Such position of the knitting instruments is shown, for example in FIGS. 5 and 6, wherein one of the knitting needles 2, of the latch type in the illustrated embodiment, and part of a conventional stitch comb 17 are clearly seen. In the clutch position thus attained, severance of the drive connection between the knitting instruments and the weft storage 11 is effected with the thread feeder 6. Moreover, at the severing location 14, at which suitable shears (FIG. 1) are provided, the severance of the weft present in the knitted web 3 from the weft lengths remaining in the thread storage 11 can now occur. Furthermore, the end 4"of the broken weft extending to the holder member 9 is then completely removed.

To automatically fill the weft storage 11 by means of the thread feeder 6, the latter is then brought into the starting position thereof and the weft storage 11 is simultaneously set in the filling position thereof. Moreover, the weft storage 11 can be revolved both in direction of the arrow 20 as well as in the opposite rotary direction of the arrow 16 until it is determined by suitable conventional sensing means, Not shown in the drawing, that the last weft length still present in the weft storage 11 has been made ready for connection with the weft lengths that are to be newly inserted. In this filling position, the guiding eye 7 of the thread feeder 6 assumes the position of the point 15 in FIG. 4. The filling position of the weft storage 11 is shown in FIG. 5. In this position, the end 4of the weft 4 extending from the supply coil 5 is again threaded through the guiding eye 7 in case it has slipped out of the latter and is secured to the holder member 9'of the weft insertion wheel 10. y

The completion of the subsequent refilling of the thread storage 11 is clarified by the view of FIG. 6. In the illustrated embodiment, each of the two weft insertion wheels 10 and has eight holder members 9, 9'. Only the weft insertion wheel 10 located in the vicinity of the edge 18 of the knitted web shown in FIG. 1 is illustrated in FIGS. 5 and 6. Since four wefts 4 were still present in the weft storage 11 before it is refilled, as seen in FIG. 5, four additional wefts became stored after two complete revolutions of the thread feeder or inserter 6, starting from the clutch position at point 13 in FIG. 3, with the simultaneous rotation of the weft insertion wheels 10 and 10a in direction of the arrow 16. Thereby, the weft length 4a, which was severed from the last knitted weft and which remains in the weft storage 11, is again located in the original insertion position thereof, so that upon restoration of the drive connection between the knitting instruments and the weft storage, which also occurs at the point 13 in FIG. 3, it can be fed or disposed behind the knitting needles 2 by the indicated stitch comb l7 and can be knitted into the web 3 that is located above the knocking-over bar 19.

The severance and restoration of the drive connection between the knitting instruments, on the one hand, and the thread storage 11 and the thread feeder 6, on the other hand, occur expediently through jaw clutch couplings or gear couplings with search gearing or toothing. Such couplings or clutches only engage in a specific position which can be selected so that it corresponds, for example, to the clutch location at point 13 of FIG. 3. The required number of revolutions of the thread feeder 6 can be controlled in accordance with the number of holder members 9 and the weft lengths remaining in the weft storage 11 through conventional electrical or mechanical counting devices.

In FIG. 5 there is shown quite schematically the drive connection for the weft storage 11 and knitting instru ments 1, 2, 19 as intersecting dot-dash lines, a clutch of the aforementioned type being connected between the weft storage and the knitting instruments. Also shown very schematically in FIG. 1 is a feeler or sensing member 20 normally engaging the weft 4 and releasable by the breaking of the weft 4 to open the power circuit to the knitting machine and thereby shut down the machine.

For more specific details regarding the structure of warp knitting machines which may be utilized or modified for use in carrying out the method of operation in accordance with the invention of the instant application, reference may be had, for example, to application, Ser. No. 19,431 of S. Fiirst, filed Mar. 13, I970 and assigned to the same assignee as that of the instant application, as well as to application, Ser. No. 58,008

6 of S. Fiirst, filed July 24, 1970 and also assigned to the same assignee. We claim:

1. Method of operating a warp knitting machine having a weft insertion device, a weft storage for the weft that is to be inserted, a plurality of knitting instruments drivingly connectible to the weft storage, and a machine shut-down device activated at interruption of a weft being fed to the weft storage, which comprises, after interruption of a weft running to the weft storage and after shutdown of the machine, severing the drive connection between the weft storage and the knitting instruments, removing the lengthl ll 11 of weft extending from the break thereof to the weft storage, thereafter placing the weft storage in filling position, automatically refilling the weft reserve remaining in the weft storage, and restoring the drive connection between the weft storage and the knitting instruments so as to resume the knitting process.

2. Method according to claim 1 wherein severance of the drive connection between the weft storage and the knitting instruments is effected by disengaging a clutch connected therebetween, and restoring the drive connection is effected by reengaging the clutch, both the severance and restoration of the drive connection being effected when the clutch members are at a predetermined position.

3. Method according to claim 1 wherein the weft storage is refilled by initially bringing both the weft storage as well as a weft inserter into a starting position,

and thereafter threadiPg th weft M0 the weft inserter and depositing the we t at t e we t storage by means of the weft inserter. 

1. Method of operating a warp knitting machine having a weft insertion device, a weft storage for the weft that is to be inserted, a plurality of knitting instruments drivingly connectible to the weft storage, and a machine shut-down device activated at interruption of a weft being fed to the weft storage, which comprises, after interruption of a weft running to the weft storage and after shut-down of the machine, severing the drive connection between the weft storage and the knitting instruments, removing the length11111 of weft extending from the break thereof to the weft storage, thereafter placing the weft storage in filling position, automatically refilling the weft reserve remaining in the weft storage, and restoring the drive connection between the weft storage and the knitting instruments so as to resume the knitting process.
 2. Method according to claim 1 wherein severance of the drive connection between the weft storage and the knitting instruments is effected by disengaging a clutch connected therebetween, and restoring the drive connection is effected by reengaging the clutch, both the severance and restoration of the drive connection being effected when the clutch members are at a predetermined position.
 3. Method according to claim 1 wherein the weft storage is refilled by initially bringing both the weft storage as well as a weft inserter into a starting position, and thereafter threading the weft into the weft inserter, and depositing the weft at the weft storage by means of the weft inserter. 